Nitrogen removal efficiency and capacity in biofilms with biologically hydrolysed sludge as a carbon source

1994 ◽  
Vol 30 (6) ◽  
pp. 63-71 ◽  
Author(s):  
A. Æsøy ◽  
H. Ødegaard
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Volatile Fatty Acids ◽  
Denitrification Rate ◽  
Diffusion Resistance ◽  
Soluble Organic Matter ◽  
Biological Sludge ◽  
Sludge Hydrolysis

The possibility of using biologically hydrolysed sludge as carbon source for the denitrification process in biofilms has been investigated. The goal of the biological sludge hydrolysis process is a high degree of solubilization of the organic matter in the sludge. The soluble organic matter is best dominated by readily biodegradable compounds. The biological hydrolysis of chemical/biological raw sludge resulted in a degree of solubilization (yield) of 11%, where about 84% of the soluble organic matter originated from protein materials. The solubilized nitrogen was found as ammonium-nitrogen. The sludge was composed of 70% chemical sludge and 30% biological sludge. On average 66% of the soluble organic matter was volatile fatty acids. Only the volatile fatty acids were utilized as carbon source in the denitrifying biofilm. The biofilms were around 1000 μm thick, and the denitrification rate with respect to the concentration of volatile fatty acids could be described by a hyperbolic Monod-type function. The effect of the diffusion resistance in the biofilms was reflected by the use of an artificial “half-saturation” constant, K*CODVFA = 3 mg CODVFA/l. The maximum denitrification rate was found to be rmaxNO3-N = 0.57 g NO3-N/g VS· d. The stoichiometric consumption ratio between soluble organic matter and nitrate was 4.5 g CODVFA/g NO3-N on average. A simulation example on the nitrogen removal capacity when the carbon source is provided by sludge hydrolysis is given.

Denitrification in biofilms with biologically hydrolysed sludge as carbon source

1994 ◽  
Vol 29 (10-11) ◽  
pp. 93-100 ◽  
Author(s):  
A. Æsøy ◽  
H. Ødegaard
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Volatile Fatty Acids ◽  
Denitrification Rate ◽  
Diffusion Resistance ◽  
Yield Coefficient ◽  
Consumption Ratio ◽  
Half Saturation Constant ◽  
Denitrification Kinetics ◽  
Biofilm Process

This paper is a contribution to the understanding of the possibilities and limitations of the socalled HYPRO-concept, a compact process design for nutrient removal where the carbon source for the denitrification process is provided by hydrolysis of the pre-precipitated sludge. The objective of the study was to investigate how efficiently biologically hydrolysed sludge is utilized in a biofilm process. The results show that only the volatile fatty acids in the hydrolysed sludge were utilized as carbon source. The denitrification kinetics were not influenced by the particulate and colloidal materials that adsorbed to the biofilm. The biofilms in the present study were thick (> 900 μm) and porous, and the denitrification rate could be described by a hyperbolic Monod-type function with respect to both the nitrate and the volatile fatty acids concentration. The diffusion resistance is included and expressed by an artificial “half-saturation” constant, K*. The maximum denitrification rate was rNO3−Nmax = 0.567 g NO3-N/g VS · d, K*NO3−N = 1.4 mg NO3-N/l and K*CODVFA = 3.0 mg CODVFA/l. The stoichiometric consumption ratio between soluble COD and nitrate was found to be 4.5 ± 0.6 g CODs/g NO3-N. The specific growth rate was μ = 0.61 ± 0.12 d−1 and the yield coefficient was YCOD = 0.22 ± 0.04 g VS/g COD.

Utilising laboratory experiments as a first step to introduce primary sludge hydrolysis in full-scale

2008 ◽  
Vol 57 (9) ◽  
pp. 1397-1403 ◽  
Author(s):  
K. Jönsson ◽  
A. Pottier ◽  
I. Dimitrova ◽  
U. Nyberg
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Carbon Source ◽  
Laboratory Tests ◽  
Laboratory Experiments ◽  
Treatment Plant ◽  
Full Scale ◽  
Soluble Organic Matter ◽  
Primary Sludge ◽  
Sludge Hydrolysis

Laboratory experiments have been utilised as a tool to determine the possible yield of soluble COD and VFAs from settled influent and preprecipitated sludge at Klagshamn wastewater treatment plant and to determine the degradability of the organic matter. The release of ammonium and orthophosphate from the hydrolysed sludge has been estimated. It is possible to produce soluble organic matter of good quality from settled influent and preprecipitated sludge at Klagshamn WWTP. Denitrification rates of 3.1 mg NO3-N/(g VSS × h) were found for the hydrolysate in laboratory tests. Owing to the low phosphate concentrations in the hydrolysate from preprecipitated sludge, it shows a potential for postdenitrification despite stringent phosphorus outlet demands. Calculations based on data gained from the laboratory experiments show that about 50% of the external carbon source used today can be saved with minor changes in the plant operation except that the hydrolysis has to be established. Based on these findings, full-scale experiments with internal hydrolysis in the primary clarifiers were scheduled in one of the two lines at Klagshamn WWTP for the summer of 2007.

Combined Pre-Precipitation, Biological Sludge Hydrolysis and Nitrogen Reduction - A Pilot Demonstration of Integrated Nutrient Removal

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1057-1066 ◽  
Author(s):  
G. H. Kristensen ◽  
P. E. Jørgensen ◽  
R. Strube ◽  
M. Henze
Keyword(s):  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Volatile Fatty Acids ◽  
Anaerobic Sludge ◽  
Biological Nitrogen Removal ◽  
Nitrogen Reduction ◽  
Biological Sludge ◽  
Sludge Hydrolysis ◽  
Biological Nitrogen ◽  
Phosphorus Reduction

A pilot study was performed to investigate advanced wastewater treatment by preprecipitation in combination with biological nitrogen removal supported by biological sludge hydrolysis. The influent wastewater was pretreated by addition of a pre-polymerized aluminium salt, followed by flocculation and sedimentation. Chemical pretreatment resulted in 60% COD-reduction and 75% phosphorus reduction. The chemically precipitated primary sludge was exposed to anaerobic sludge hydrolysis at retention times of 1 and 2 days at temperatures in the range of 15-30°C. At a retention time of two days at 20°C, resulting solubilization was 10-13% of the suspended COD. The liquid phase of the hydrolyzed sludge, the hydrolysate, was separated from the suspended fraction by centrifugation and added to the biological nitrogen removal stage to support denitrification. The hydrolysate COD consisted mainly of volatile fatty acids, resulting in high denitrification rates. Nitrogen reduction was performed based on the Bio-Denitro principle in an activated sludge system. Nitrogen was reduced from 45 mg/l to 9 mg/l and phosphorus was reduced from 11 mg/l to 0.5 mg/l. The sludge yield was low, approx. 0.3-0.4 gCOD/gCOD removed. This in combination with the efficient pretreatment emphasizes the concept as well suited for compact advanced treatment including nutrient removal.

Pre-Precipitation Facilitates Nitrogen Removal without Tank Expansion

1990 ◽  
Vol 22 (7-8) ◽  
pp. 85-92 ◽  
Author(s):  
Ingemar Karlsson ◽  
Gunnar Smith
Keyword(s):  
Waste Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Waste Water Treatment ◽  
Chemical Precipitation ◽  
Sewage Water ◽  
Laboratory Studies ◽  
Denitrification Process

Chemically coagulated sewage water gives an effluent low in both suspended matter and organics. To use chemical precipitation as the first step in waste water treatment improves nitrification in the following biological stage. The precipitated sludge contains 75% of the organic matter in the sewage and can by hydrolysis be converted to readily degradable organic matter, which presents a valuable carbon source for the denitrification process. This paper will review experiences from full-scale applications as well as pilot-plant and laboratory studies.

Nutritional studies with sheep fed conserved ryegrass. 2. Silage supplemented with dried grass or barley

1980 ◽  
Vol 94 (1) ◽  
pp. 219-227 ◽  
Author(s):  
C. G. Wernli ◽  
R. J. Wilkins
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Energy Demand ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Nitrogen Retention ◽  
High Rate ◽  
Physical Factors ◽  
Digestible Organic Matter ◽  
Nutritional Studies

SummaryGrass silage (21.0 % D.M.) was given ad libitum to sheep together with supplements of rolled barley, dried-grass pellets or dried-grass wafers at 12 and 25 g organic matter (OM)/kg0·75.Intake of silage was greater with supplement at 12 g/kg0·75 but total intake of OM and digestible organic matter (DOM) increased with increasing supplement. Intake of OM was higher with the pellet supplement than with other supplements. Intake of DOM, however, did not differ between the pellet and barley treatments, but was lower with wafers.Concentrations of ammonia and total volatile fatty acids and the molar proportions of butyric and higher volatile fatty acids were higher when silage was supplemented with barley than with dried grass. Mean rumen retention times of silage and of supplement were highest in the barley-supplemented treatments. Dried-grass wafers were retained longer than dried-grass pellets. Supplement treatments did not differ significantly for eating and ruminating times, rumen fluid volume and pH, digestion rate in the rumen and nitrogen retention.At the low supplement rate silage consumption may have been controlled by factors associated directly with the silage, whereas at the high rate intake was limited either by physical factors or by the potential energy demand of the animals.

Volatile fatty acids and sulfide in pressure mains

1995 ◽  
Vol 31 (7) ◽  
pp. 169-179 ◽  
Author(s):  
T. Hvitved-Jacobsen ◽  
K. Raunkjær ◽  
P. H. Nielsen
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Production Rate ◽  
Volatile Fatty Acids ◽  
Production Rates ◽  
Net Production ◽  
Toc Removal ◽  
Sulfide Production ◽  
Transformation Of Organic Matter ◽  
High Sulfide

The main objective was to study the anaerobic transformation of organic matter and sulfide production during wastewater transportation. Emphasis was on the transformation of easily biodegradable organic matter in terms of volatile fatty acids (VFA). Samples from two intercepting pressure mains located in the Northern part of Jutland, Denmark, were taken. The concentration of VFA in the wastewater varied considerably during day and night, being typically between 5 and 50 g/m3. A net production as well as a net removal of VFA was seen during transportation in the pressure mains probably depending on the quality and quantity of the organic matter. Typically 85% of the VFA was acetate and 10% propionate; the remainder was formate, n-butyrate and iso-butyrate. Observed sulfide production rates from the sewer biofilms were typically 0.05 and 0.005 g S/m2 h at 12 and 4 °C, respectively. A high sulfide production rate corresponded with a high VFA concentration. TOC removal was observed in the pressure mains.

scholarly journals Producing Omega-3 Polyunsaturated Fatty Acids: A Review of Sustainable Sources and Future Trends for the EPA and DHA Market

Resources ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 148
Author(s):  
Laura Oliver ◽  
Thomas Dietrich ◽  
Izaskun Marañón ◽  
Maria Carmen Villarán ◽  
Ramón J. Barrio
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Polyunsaturated Fatty Acids ◽  
Volatile Fatty Acids ◽  
Good Alternative ◽  
Future Market ◽  
Omega 3 ◽  
Alternative Pathways ◽  
Healthy Nutrition ◽  
Main Challenge

Omega-3 polyunsaturated fatty acids (Omega-3 PUFA) are recognized as being essential compounds for human nutrition and health. The human body generates only low levels of Omega-3 PUFA. Conventional sources of Omega-3 PUFA are from marine origin. However, the global growth of population combined with a better consumer understanding about healthy nutrition leads to the fact that traditional sources are exhausted and therefore not enough to satisfy the demand of Omega-3 PUFA for human diet as well as aquaculture. Microalgae cultivated under heterotrophic conditions is increasingly recognized as a suitable technology for the production of the Omega-3 PUFA. The high cost of using glucose as main carbon source for cultivation is the main challenge to establish economical feasible production processes. The latest relevant studies provide alternative pathways for Omega-3 PUFA production. As preliminary results show, volatile fatty acids (VFA) recovered from waste stream could be a good alternative to the use of glucose as carbon source in microalgae cultivation. The purpose of this paper is to highlight the actual situation of Omega-3 PUFA production, sources and market request to provide a summary on sustainable sources that are being investigated as well as present and future market trends in Omega-3 market.

Digestion by ruminant lambs of a diet containing formaldehyde-treated casein

1971 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
GJ Faichney ◽  
RH Weston
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Plasma Levels ◽  
Volatile Fatty Acids ◽  
Amino Nitrogen ◽  
Ammonia Nitrogen ◽  
Casein Diet ◽  
Plasma Urea ◽  
Urea Level

Digestion of a diet containing 10% casein, either untreated or treated with formaldehyde, was studied in crossbred wether lambs. The treatment prevented breakdown of the casein in rumen liquor in vitro. There was a highly significant decrease in organic matter digestion in the rumen when the treated casein diet was given to the lambs. This was accounted for by increases in the amounts of protein and starch passing to the intestines. There was a 60 % increase in the amount of non-ammonia nitrogen and a 55 % increase in the amount of starch digested in the intestines. The concentrations of volatile fatty acids and ammonia in the rumen were significantly lower. There were increases in the plasma levels of insulin and �-amino nitrogen and a decrease in the plasma urea level in response to the treatment.

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